The present invention is related generally to personal watercraft. More specifically, the present invention is related to personal watercraft having adjustable sponsons.
Personal watercraft have become increasingly popular in recent years. A personal watercraft, also known as a xe2x80x9cjet skixe2x80x9d typically has a bottom hull, handle bars for steering, a tunnel within the bottom hull, a jet pump located within the bottom tunnel, and an engine within the hull under the top deck for driving the jet pump. The jet pump typically pulls in water from the front of the tunnel under the boat, and discharges the water at high velocity through a steerable nozzle at the rear of the boat. The handle bars are typically coupled to the nozzle, which is the steering mechanism for the personal watercraft. The watercraft commonly has a straddle-type seat and foot wells disposed on either side of the seat.
Early watercraft often had longitudinal chines running underneath the bottom hull, and sometimes had steps located in the rear portion of the bottom hull, for reducing porpoising by extending the length of the boat while not extending the length of wetted surface. Steering, as previously indicated, was primarily effected by turning the handle bars coupled to the nozzle, which could be steered from side to side to direct the water jet in the desired direction and thereby steer the personal watercraft. The steerable nozzle sometimes had a small rudder on the nozzle, also for aiding in steering the watercraft.
Early personal watercraft sometimes skidded around corners wider than the driver desired. Sometimes, boats would turn 180xc2x0, despite the driver""s intent to make a sharp 90xc2x0 turn. This lack of control at high speeds during aggressive maneuvers was later addressed by adding sponsons to the personal watercraft.
The term xe2x80x9csponsonxe2x80x9d has come to have different meanings in different contexts. Historically, sponsons were floatation devices or outriggers for stabilizing a boat in rough water. The sponsons could be lowered or thrown to stabilize a boat in rough water, for example, while fishing. The sponsons could be later raised for traveling through the water. The term sponson has also been used to refer to the outrigger on an outrigger canoe. As used in the personal watercraft industry, and as used in the present application, the term sponson refers to a device having a substantially hydrodynamic shape to aid the watercraft in stabilizing straight ahead progress through the water and to aid in executing turns in the water. The personal watercraft sponsons are dimensioned and configured to have a fin or blade having an outwardly extending edge which penetrates below the water level during normal use. The personal watercraft""s sponson will penetrate below the water surface when the personal watercraft is at rest, in calm water, even with no rider. The sponson typically has an outwardly extending lower surface which rides on the water when the boat is planning.
Sponsons provide lift at the rear of the personal watercraft, acting to force the nose down to provide a degree of aggressiveness. Sponsons that provide harder, sharper cornering often also provide decreased straight line stability. The more aggressive design often has a xe2x80x9ctippyxe2x80x9d feeling when the rider shifts their weight. This tippy feeling is accepted by experienced drivers, but maybe unsettling to experienced drivers. Sponsons are typically designed together with the personal watercraft hull, for a particular model and year. Various considerations go into the hull and sponson design, including the desired degree of stability, desired lift provided by the sponson, and the degree of aggressiveness desired for that model and model year. Different drivers desiring different features can select varying personal watercraft having the desired handling characteristics.
What would be desirable are personal watercraft having sponsons which can vary according to the desired handling characteristics of the driver. What would be advantageous are sponsons which can be changed from an aggressive handling mode to a gentler riding mode.
The present invention provides adjustable angle sponsons and personal watercraft having adjustable angle sponsons. The adjustable angle sponsons include a fin or blade which can extend outwardly and downwardly away from the hull and into the water. The sponson fin includes an outward edge for penetrating beneath the water surface when the personal watercraft is at rest, in calm water, even with no passengers. The sponson fin outward edge may of course penetrate beneath the water surface under other conditions, for example, turning. The adjustable angle sponsons can include at least two angular positions. Each fin has a longitudinal axis and is adjustable between at least two positions about the axis. Adjustable angle sponsons preferably have at least two, pre-set, discrete, fixed angular locking positions for the sponson fin.
One adjustable angle sponson includes a sponson fin secured to a longitudinal shaft, with the shaft having a longitudinal key disposed along its length. The adjustable angle sponson can further include a sponson housing having a cavity therein for receiving the longitudinally inserted sponson shaft as well as a keyway within the cavity for receiving the longitudinally inserted sponson shaft key. The housing can have several keyways, providing as many angular settings for the sponson fin as there are keyways. Some sponsons have more than one key, preferably for fitting within more than one keyway concurrently. Some adjustable angle sponson shafts have splines adapted to fit within corresponding spline receiving grooves within the cap housing cavity. The adjustable angle sponsons can be set to a straight down, vertical angular position in a preferred embodiment, to provide a very responsive, aggressive handling personal watercraft. The adjustable angle sponsons also preferably provide a more upwardly angled sponson fin position relative to vertical, to provide a less aggressive handling personal watercraft when desired. The sponsons may also be configured to be adjusted between many angular positions relative to horizontal.
The present invention thus provides a personal watercraft that allows the user or driver to set the handling characteristics. The handling characteristics can be set to match the driver""s desires and experience level. The characteristics can also be set as a function of the passenger load and the expected water conditions. The present invention empowers the user to select the optimal handling characteristics for the user, rather than having these characteristics being dictated by the manufacturer.